Reversible-blade propeller



April 7, 1931. c, ELMORE 7 1,799,548

' REVERSIBLE BLADE PROPELLER Filed June 1, 1922- 4 Sheets-Sheet 1 fea /ye aZZIW/OI& INVENTOR p i 7, 931. G. c. 'ELMQRE 1,799,548

REVERSIBLE BLADE PROPELLER Filed June 1, 1928 4 Sheets-Sheet 2 April 7, 1931.

I REVERSIBLE BLADE PROPELLER Filed June 1, 1928 4 Sheets-Sheer, 3

Georye CZ'Zmra INVENTOR ATTORNEY p l 7, 1931- G. c; ELMORE REVERSIBLE BLADE PROPELLER 4 Sheets-Sheer. 4

I Filed Jung 1, 1928 Patented Apr. 7, 1931 enonen o. nrmonn, or rrnnon, rnonma REVERSIBLE-BLADE PBOPELLER -Application filed June 1, 1928. Serial no. 282,220.

This invention relates to improvements in propellers and has for an object the provision of means whereby the blades of a propeller may be reversed to control the direc- 8 tion of thrust, and their pitch regulated to controlthe degree of thrust, the invention being useful for either air or watercraft. Another obj ect of the invention is the provision of novel means for mounting the arms 10 which carry the propeller blades so as to permit of rotary adjustment to regulate the pitch of or reverse the blades, together with novel means for effecting such adjustment.

With the above and other objects in view,

15 the invention furtherincludes the following novel features and details of construction,- to be hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

2 In the drawings Figure 1- is a fragmentary plan view partly in section illustrating the invention.

' Figure 2 is a fragmentary front view partly in section.

* Fi re 3 isa section taken substantially on the line 3-3 of Figure 1, a part of one of the eccentrics being broken away.

Figure 4 is a detail perspective view of the hub. p

30. Figure 5 is a perspective view ofone end of the propeller shaft.

' Figure 6 is a similar 'view showing the inner end of one of the propeller arms. Figure 7 is a like view of a key.

85. Figure 8 is .a sectional view showing a slightly different form of the invention.

Figure 9 is a section taken substantially on the line 99 .ofFigure 8.

1 Figure 10 is a section on the line 10-10 of Figure 8, the-section including the'means for mounting the propeller shaft and the driving pinion for said shaft. 1

Figure 11 is a fragmentary perspective view of the inner end of the adjusting rod.

46 Figure 12 is a like view of the inner end of one of the propeller arms.

Figure 13 is a deta1l perspective view of Q-.. none of the eccentric plates.

Figure l f is'a' perspective view of thehub and shaft. v l

Referring to the drawings in, detail and especially to that form of the invention. shown in Figures 1 to 7 inclusive, the reference character 15 indicates a portion of the propeller shaft whose outer end is provided with a reduced threaded portion 16 for the reception of a nut 17 the latter serving to hold a hub 18 upon the shaft. A look washer 19-is interposed between the outer face of the hub and the nut :17-

The hub 18 is provided with oppositely extending bores or sockets 20 and these sockets receive the inner ends of blade arms 21; a portion of the blades being shown at 22.

The inner ends of the blade arms 21' are 66 provided with enlargements 23 forming annular. shoulders 24. and threadedly secured within the sockets 20 and bearing a ainst these shoulders are the inner ends of s eeves 25. The arms 21 are thus mountedfor'rotation within the hub. The heads 23 are provided with slots 26 whose opposite walls are outwardly flared as shown at 27. The slots 26 are adapted to receive keys 28 which are also received within slots 29 provided in 16 the shaft 15. The keys 28 thus lock the hub 18 and shaft 15 agiaxilnst relative rotation and serve as stops to it rotary movement of the arms 21 in op osite directions.

Slidingly mounte upon the shaft 15 is a at collar'30 having a flange 31 and secured to this collar is a late 32 whose diameter is the same as the diameter of the flange 31, so that an annular groove 32 is provided within which is swiveled a collar 33. The collar. 30 and the plate 32 may be made of any 'suitable material, but are preferably formed of bronze.

Extending radiall from'the collar 33 are I tapered arms 34 and pivoted upon the enter to ends of these arms 34 are adjusting arms' 35.

The outer ends of the arms 35 are hook shaped and have their extremities pivotally mounted. as shown at 36 in notches] 37 rdvided in an eccentric 38, oneof which is,

keyed upon each of the arms 21. By mov-' ing the collar 30 longitudinally of the shaft I 15, the blade arms 21 will-berotated, the

degree of rotationbein' governed by the d egree of'moveme'nt of. ecol lar 30. H

is provided with oppositely exten ing inclined ears 41 for connection with operating or reverse rods (not shown). These rods may extend to the cock pit or other convenient place within either an aircraft or a watercraft.

In Figures 8 to 14 of the drawings, the propeller shaft 42 is hollow and carries a hollow hub having an integral inner section 43 and an outer section .44. This outersection is secured to the inner section by means of screws 45 so that in effect the sections form a unitary structure. A plate 46 closes the outer face of the hub, while a plate 47 having an opening 48 therein closes the inner face of the hub. I

Threadedly secured within the hub are diametrically extending sleeves 49 within which are rotatably mounted the inner ends of arms 50 which carry propeller blades. 51. These arms 50 are provided at their inner ends with collars 52 against which the sleeves 49 abut so that these propeller arms 50 are swiveled within the hub. The arms '50 are provided with an extension 53 whose shaped opening 54 which is provided in an eccentric plate 55. The plate 55 is provided with anotch 45 for the reception of a pin 57. The pins 57 extend in opposite. directions and are spaced upon opposite sides of a head 58. This head extends laterally at one end of an operating rod 59 which rod mayextend to the cock pit or other convenient place within a craft. For this purpose, the extended end of the rod 59 carries a bearing 60 which may have connection with a suitable rod extension. It will be apparent that by moving the rod 09 longitudinally, the propeller arms 50 may be rotated in accordance with the degree of such movement.

The shaft 42 may be also provided with bearings 61 and may have secured thereon a plnion 62,,so that this shaft may be driven by suitable gearing from a suitable motor, the speed of the shaft 42 being geared down from the speed of the motor. This provides what may be termed an oflset shaft, and the shaft 15 in the form of the invention previously described may also be an offset shaft. This will permit of the use of a relatively light motor operating at high speed to develop increased horsepower so that the propellers .may' be geared down for greater efliciency.

Through the use of the invention, the pitch of the blades may be adjusted as desired, and the pitch reversed so as to reverse the direction of thrust of the blades.

The invention is susceptible of various changes in its form, proportions and minor details of construction and the right is herein reserved to make such changes as properly fall within the scope of the appended claims.

Having described the invention what is claimed is v 1. A reversing mechanism for propellers comprising in combination, a hub adapted for attachment to a shaft, arms mounted for rotation dn said hub, blades carried by said arms, notched eccentrics mounted upon the rotatable arms, a collar adapted .to be swiveled upon and slide longitudinally of the shaft, and adjusting arms having one of their ends pivotally connected with the collar and their other ends pivotally secured within the notches of the eccentricsto control the pitch of the blades by longitudinal movement of thecollar.

2. A reversing mechanism for propellers including a power shaft having slots, a hub secured to the power shaft and having oppositely disposed screw threaded bores,.prope1- ler arms extending in said bores, blades secured to said arms, heads formed on said arms and abutting the inner walls of said bores,sleeves threaded in said bores to support said arms and bearing against the heads to adjustably limit the outward movement of the heads in the bores, said heads having slots with the walls thereof flared outwardly, keys located insaid slots and the slots in the heads adapted to permit limited rotation of the arms in either direction, and means for moving said arms to change the pitch of the blades.

3. A reversing mechanism for propellers comprising a hub secured to a power shaft,

propeller arms mounted in said hub, driving means between the arms andthe power shaft,

bladessecured to the arms, eccentrics secured to said arms'and having notches, plates on said arms and disposed on opposite sides of the eccentrics and projecting beyond the peripheries thereof, a slidable operating collar mounted on the power shaft. arms pivoted to the collar and having oppositely disposed hook-shaped ends received in the notches of the eccentrics'and pivoted to the plates to move the blades by the collar and thereby vary the pitch ofsaid blades.

In testimony whereof I affix my signature.

GEORGE C. ELMORE. 

